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<h2><span class="refentrytitle">Function all_to_all</span></h2>
<p>boost::mpi::all_to_all — Send data from every process to every other process. </p>
</div>
<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="../mpi/reference.html#doxygen.collectives_8hpp" title="Header &lt;boost/mpi/collectives.hpp&gt;">boost/mpi/collectives.hpp</a>&gt;

</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">void</span> <span class="identifier">all_to_all</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="classboost_1_1mpi_1_1communicator.html" title="Class communicator">communicator</a> <span class="special">&amp;</span> comm<span class="special">,</span> 
                  <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="special">&amp;</span> in_values<span class="special">,</span> 
                  <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="special">&amp;</span> out_values<span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">void</span> <span class="identifier">all_to_all</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="classboost_1_1mpi_1_1communicator.html" title="Class communicator">communicator</a> <span class="special">&amp;</span> comm<span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span> in_values<span class="special">,</span> 
                  <span class="identifier">T</span> <span class="special">*</span> out_values<span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">void</span> <span class="identifier">all_to_all</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="classboost_1_1mpi_1_1communicator.html" title="Class communicator">communicator</a> <span class="special">&amp;</span> comm<span class="special">,</span> 
                  <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="special">&amp;</span> in_values<span class="special">,</span> <span class="keyword">int</span> n<span class="special">,</span> 
                  <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="special">&amp;</span> out_values<span class="special">)</span><span class="special">;</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">void</span> <span class="identifier">all_to_all</span><span class="special">(</span><span class="keyword">const</span> <a class="link" href="classboost_1_1mpi_1_1communicator.html" title="Class communicator">communicator</a> <span class="special">&amp;</span> comm<span class="special">,</span> <span class="keyword">const</span> <span class="identifier">T</span> <span class="special">*</span> in_values<span class="special">,</span> <span class="keyword">int</span> n<span class="special">,</span> 
                  <span class="identifier">T</span> <span class="special">*</span> out_values<span class="special">)</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="id-1.3.24.7.5.6.4"></a><h2>Description</h2>
<p><code class="computeroutput">all_to_all</code> is a collective algorithm that transmits <code class="computeroutput">p</code> values from every process to every other process. On process i, jth value of the <code class="computeroutput">in_values</code> vector is sent to process j and placed in the ith position of the <code class="computeroutput">out_values</code> vector in process <code class="computeroutput">j</code>. The type <code class="computeroutput">T</code> of the values may be any type that is serializable or has an associated MPI data type. If <code class="computeroutput">n</code> is provided, then arrays of <code class="computeroutput">n</code> values will be transferred from one process to another.</p>
<p>When the type <code class="computeroutput">T</code> has an associated MPI data type, this routine invokes <code class="computeroutput">MPI_Alltoall</code> to scatter the values.</p>
<p>
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<td><p><span class="term">Parameters:</span></p></td>
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<td><p><span class="term"><code class="computeroutput">comm</code></span></p></td>
<td><p>The communicator over which the all-to-all communication will occur.</p></td>
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<td><p><span class="term"><code class="computeroutput">in_values</code></span></p></td>
<td><p>A vector or pointer to storage that contains the values to send to each process, indexed by the process ID number.</p></td>
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<tr>
<td><p><span class="term"><code class="computeroutput">out_values</code></span></p></td>
<td><p>A vector or pointer to storage that will be updated to contain the values received from other processes. The jth value in <code class="computeroutput">out_values</code> will come from the procss with rank j. </p></td>
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<div class="copyright-footer">Copyright © 2005-2007 Douglas Gregor,
      Matthias Troyer, Trustees of Indiana University<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at &lt;ulink url="http://www.boost.org/LICENSE_1_0.txt"&gt;
        http://www.boost.org/LICENSE_1_0.txt &lt;/ulink&gt;)
      </p>
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